The invention relates to an arrangement for adjusting the spacing distance of the lower roller cylinders of a plurality of adjacently disposed drawng or drafting roller units of a spinning machine. The lower roller cylinders of such machines extend in the machine longitudinal direction and are borne in a plurality of bearing positions which each include a bearing seat fixedly attached to a guide carrier, wherein all bearing seats of a lower roller cylinder are detached from the guide carrier during adjustment of the spacing distance. The bearing seats are then jointly moved into the desired position together with the lower roller cylinder, and subsequently again fixedly attached to the guide holder or carrier.
Spinning machines of the kind mentioned above are often used in practice. If a sliver is being spun after a batch change, which sliver is of a different staple length than the previous batch, it is necessary to adjust the clamping distance between the sets of drafting rollers. It is not usually a problem to carry out this adjustment for the upper rollers which are not formed as cylinders extending in machine longitudinal direction, but which are pressure rollers that are arranged as single rollers or as a unit with two adjacently arranged rollers. The adjustment of the spacing distance of the lower roller cylinders, however, creates an extensive amount of work in practice, which task can only be completed by a large number of persons, a so called assembly crew. All bearing seats need to be detached by the persons of the assembly crew whereby the respective lower roller cylinders have to be held by several persons, to be subsequently and evenly returned to the desired position, and again held until the bearing seats are again attached to the guide carrier. This is clearly a time consuming and expensive assembly operation in connection with the resetting or conversion of a spinning machine.
With single drafting roller arrangements of a drafting roller combination of a drawing frame it is known from German Published Unexamined Patent application (DE-OS) 28 52 692 to provide a control device for the adjustment of the clamping distance. With this arrangement the roller bearings arranged on either side of the drawing roller are retained in bearing slides which are slidable on toothed racks. Both the upper and lower rollers are simultaneously moved, while on the other hand each roller pair is moved singly. Such an adjustment arrangement is however not utilized in connection with spinning machines where there is provided a plurality of adjacently arranged drafting units, the lower rollers of which are designed as lower roller cylinders.